Milking the data: Measuring milk off-take in extensive livestock systems. Experimental evidence from Niger
通过尼日尔的实地实验，比较了不同回忆式问卷工具与12个月物理监测记录在测量牛奶产量上的准确性，发现回忆法能获得合理准确的估计，并给出了问卷设计的优劣排序，对改进家户调查数据质量有直接指导意义。
Milk is an important source of cash and nutrients for many households in developing countries. Yet, our understanding of the role of dairy production in livelihoods and nutritional outcomes is hindered by the lack of decent quality household survey data. Data on milk off-take for human consumption are difficult to collect in household surveys for a number of reasons which make accurate recall challenging for the respondent (continuous production and seasonality among others), introducing possibly severe biases in the computation of full household incomes and farm sales, as well as in the estimation of the contribution of livestock (specifically dairy) production to agricultural value added and the livelihoods of rural households. This paper presents results from a validation exercise implemented in Niger, where alternative survey instruments based on recall methods were administered to randomly selected households, and compared to a 12-month system of physical monitoring and recording of milk production. The results of the exercise show that reasonably accurate estimates via recall methods are possible, and provide a clear ranking of questionnaire design options that can inform future survey operations.